acpi: Move common tables helper functions to common lib

Some of the routines in ACPI driver/acpi/tables.c can be shared with
parsing CDAT. CDAT is a device-provided data structure that is formatted
similar to a platform provided ACPI table. CDAT is used by CXL and can
exist on platforms that do not use ACPI. Split out the common routine
from ACPI to accommodate platforms that do not support ACPI and move that
to /lib. The common routines can be built outside of ACPI if
FIRMWARE_TABLES is selected.

Link: https://lore.kernel.org/linux-cxl/CAJZ5v0jipbtTNnsA0-o5ozOk8ZgWnOg34m34a9pPenTyRLj=6A@mail.gmail.com/
Suggested-by: "Rafael J. Wysocki" <rafael@kernel.org>
Reviewed-by: Hanjun Guo <guohanjun@huawei.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Acked-by: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Link: https://lore.kernel.org/r/169713683430.2205276.17899451119920103445.stgit@djiang5-mobl3
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

2 files changed, 1 insertions, 173 deletions

diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
index cee82b473dc50..c0a2d43f8451a 100644
--- a/drivers/acpi/Kconfig
+++ b/drivers/acpi/Kconfig
@@ -12,6 +12,7 @@ menuconfig ACPI
 	select PNP
 	select NLS
 	select CRC32
+	select FIRMWARE_TABLE
 	default y if X86
 	help
 	  Advanced Configuration and Power Interface (ACPI) support for 
diff --git a/drivers/acpi/tables.c b/drivers/acpi/tables.c
index 8ab0a82b4da41..c1516337f6682 100644
--- a/drivers/acpi/tables.c
+++ b/drivers/acpi/tables.c
@@ -37,18 +37,6 @@ static struct acpi_table_desc initial_tables[ACPI_MAX_TABLES] __initdata;
 
 static int acpi_apic_instance __initdata_or_acpilib;
 
-enum acpi_subtable_type {
-	ACPI_SUBTABLE_COMMON,
-	ACPI_SUBTABLE_HMAT,
-	ACPI_SUBTABLE_PRMT,
-	ACPI_SUBTABLE_CEDT,
-};
-
-struct acpi_subtable_entry {
-	union acpi_subtable_headers *hdr;
-	enum acpi_subtable_type type;
-};
-
 /*
  * Disable table checksum verification for the early stage due to the size
  * limitation of the current x86 early mapping implementation.
@@ -237,167 +225,6 @@ void acpi_table_print_madt_entry(struct acpi_subtable_header *header)
 	}
 }
 
-static unsigned long __init_or_acpilib
-acpi_get_entry_type(struct acpi_subtable_entry *entry)
-{
-	switch (entry->type) {
-	case ACPI_SUBTABLE_COMMON:
-		return entry->hdr->common.type;
-	case ACPI_SUBTABLE_HMAT:
-		return entry->hdr->hmat.type;
-	case ACPI_SUBTABLE_PRMT:
-		return 0;
-	case ACPI_SUBTABLE_CEDT:
-		return entry->hdr->cedt.type;
-	}
-	return 0;
-}
-
-static unsigned long __init_or_acpilib
-acpi_get_entry_length(struct acpi_subtable_entry *entry)
-{
-	switch (entry->type) {
-	case ACPI_SUBTABLE_COMMON:
-		return entry->hdr->common.length;
-	case ACPI_SUBTABLE_HMAT:
-		return entry->hdr->hmat.length;
-	case ACPI_SUBTABLE_PRMT:
-		return entry->hdr->prmt.length;
-	case ACPI_SUBTABLE_CEDT:
-		return entry->hdr->cedt.length;
-	}
-	return 0;
-}
-
-static unsigned long __init_or_acpilib
-acpi_get_subtable_header_length(struct acpi_subtable_entry *entry)
-{
-	switch (entry->type) {
-	case ACPI_SUBTABLE_COMMON:
-		return sizeof(entry->hdr->common);
-	case ACPI_SUBTABLE_HMAT:
-		return sizeof(entry->hdr->hmat);
-	case ACPI_SUBTABLE_PRMT:
-		return sizeof(entry->hdr->prmt);
-	case ACPI_SUBTABLE_CEDT:
-		return sizeof(entry->hdr->cedt);
-	}
-	return 0;
-}
-
-static enum acpi_subtable_type __init_or_acpilib
-acpi_get_subtable_type(char *id)
-{
-	if (strncmp(id, ACPI_SIG_HMAT, 4) == 0)
-		return ACPI_SUBTABLE_HMAT;
-	if (strncmp(id, ACPI_SIG_PRMT, 4) == 0)
-		return ACPI_SUBTABLE_PRMT;
-	if (strncmp(id, ACPI_SIG_CEDT, 4) == 0)
-		return ACPI_SUBTABLE_CEDT;
-	return ACPI_SUBTABLE_COMMON;
-}
-
-static __init_or_acpilib bool has_handler(struct acpi_subtable_proc *proc)
-{
-	return proc->handler || proc->handler_arg;
-}
-
-static __init_or_acpilib int call_handler(struct acpi_subtable_proc *proc,
-					  union acpi_subtable_headers *hdr,
-					  unsigned long end)
-{
-	if (proc->handler)
-		return proc->handler(hdr, end);
-	if (proc->handler_arg)
-		return proc->handler_arg(hdr, proc->arg, end);
-	return -EINVAL;
-}
-
-/**
- * acpi_parse_entries_array - for each proc_num find a suitable subtable
- *
- * @id: table id (for debugging purposes)
- * @table_size: size of the root table
- * @table_header: where does the table start?
- * @proc: array of acpi_subtable_proc struct containing entry id
- *        and associated handler with it
- * @proc_num: how big proc is?
- * @max_entries: how many entries can we process?
- *
- * For each proc_num find a subtable with proc->id and run proc->handler
- * on it. Assumption is that there's only single handler for particular
- * entry id.
- *
- * The table_size is not the size of the complete ACPI table (the length
- * field in the header struct), but only the size of the root table; i.e.,
- * the offset from the very first byte of the complete ACPI table, to the
- * first byte of the very first subtable.
- *
- * On success returns sum of all matching entries for all proc handlers.
- * Otherwise, -ENODEV or -EINVAL is returned.
- */
-static int __init_or_acpilib acpi_parse_entries_array(
-	char *id, unsigned long table_size,
-	struct acpi_table_header *table_header, struct acpi_subtable_proc *proc,
-	int proc_num, unsigned int max_entries)
-{
-	struct acpi_subtable_entry entry;
-	unsigned long table_end, subtable_len, entry_len;
-	int count = 0;
-	int errs = 0;
-	int i;
-
-	table_end = (unsigned long)table_header + table_header->length;
-
-	/* Parse all entries looking for a match. */
-
-	entry.type = acpi_get_subtable_type(id);
-	entry.hdr = (union acpi_subtable_headers *)
-	    ((unsigned long)table_header + table_size);
-	subtable_len = acpi_get_subtable_header_length(&entry);
-
-	while (((unsigned long)entry.hdr) + subtable_len  < table_end) {
-		if (max_entries && count >= max_entries)
-			break;
-
-		for (i = 0; i < proc_num; i++) {
-			if (acpi_get_entry_type(&entry) != proc[i].id)
-				continue;
-			if (!has_handler(&proc[i]) ||
-			    (!errs &&
-			     call_handler(&proc[i], entry.hdr, table_end))) {
-				errs++;
-				continue;
-			}
-
-			proc[i].count++;
-			break;
-		}
-		if (i != proc_num)
-			count++;
-
-		/*
-		 * If entry->length is 0, break from this loop to avoid
-		 * infinite loop.
-		 */
-		entry_len = acpi_get_entry_length(&entry);
-		if (entry_len == 0) {
-			pr_err("[%4.4s:0x%02x] Invalid zero length\n", id, proc->id);
-			return -EINVAL;
-		}
-
-		entry.hdr = (union acpi_subtable_headers *)
-		    ((unsigned long)entry.hdr + entry_len);
-	}
-
-	if (max_entries && count > max_entries) {
-		pr_warn("[%4.4s:0x%02x] found the maximum %i entries\n",
-			id, proc->id, count);
-	}
-
-	return errs ? -EINVAL : count;
-}
-
 int __init_or_acpilib acpi_table_parse_entries_array(
 	char *id, unsigned long table_size, struct acpi_subtable_proc *proc,
 	int proc_num, unsigned int max_entries)